What are the best ways to protect outdoor furniture with polyurethane?

To protect outdoor furniture with polyurethane, follow these steps:

1. Clean the furniture thoroughly before applying polyurethane.
2. Apply a coat of polyurethane using a brush or spray.
3. Allow the polyurethane to dry completely before applying additional coats.
4. Apply multiple coats for added protection.
5. Reapply polyurethane every 1-2 years to maintain protection.